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Last active March 18, 2017 22:22
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Popping force directed graph

This graph exploits the unstable nature of forceCollide strength values outside of [0,1].

Click here for similar examples and here for an explanation of this effect.

<!DOCTYPE html>
<meta charset="utf-8">
.links line {
stroke: #999;
stroke-opacity: 0.6;
.nodes circle {
stroke: black ;
stroke-width: 0px;
<svg width="800" height="600"></svg>
<script src=""></script>
//create somewhere to put the force directed graph
var svg ="svg"),
width = +svg.attr("width"),
height = +svg.attr("height");
var radius = 10;
var nodes_data = [
{"name": "Lillian", "sex": "F"},
{"name": "Gordon", "sex": "M"},
{"name": "Sylvester", "sex": "M"},
{"name": "Mary", "sex": "F"},
{"name": "Helen", "sex": "F"},
{"name": "Jamie", "sex": "M"},
{"name": "Jessie", "sex": "F"},
{"name": "Ashton", "sex": "M"},
{"name": "Duncan", "sex": "M"},
{"name": "Evette", "sex": "F"},
{"name": "Mauer", "sex": "M"},
{"name": "Fray", "sex": "F"},
{"name": "Duke", "sex": "M"},
{"name": "Baron", "sex": "M"},
{"name": "Infante", "sex": "M"},
{"name": "Percy", "sex": "M"},
{"name": "Cynthia", "sex": "F"},
{"name": "Feyton", "sex": "M"},
{"name": "Lesley", "sex": "F"},
{"name": "Yvette", "sex": "F"},
{"name": "Maria", "sex": "F"},
{"name": "Lexy", "sex": "F"},
{"name": "Peter", "sex": "M"},
{"name": "Ashley", "sex": "F"},
{"name": "Finkler", "sex": "M"},
{"name": "Damo", "sex": "M"},
{"name": "Imogen", "sex": "F"}
//Sample links data
//type: A for Ally, E for Enemy
var links_data = [
{"source": "Sylvester", "target": "Gordon", "type":"A" },
{"source": "Sylvester", "target": "Lillian", "type":"A" },
{"source": "Sylvester", "target": "Mary", "type":"A"},
{"source": "Sylvester", "target": "Jamie", "type":"A"},
{"source": "Sylvester", "target": "Jessie", "type":"A"},
{"source": "Sylvester", "target": "Helen", "type":"A"},
{"source": "Helen", "target": "Gordon", "type":"A"},
{"source": "Mary", "target": "Lillian", "type":"A"},
{"source": "Ashton", "target": "Mary", "type":"A"},
{"source": "Duncan", "target": "Jamie", "type":"A"},
{"source": "Gordon", "target": "Jessie", "type":"A"},
{"source": "Sylvester", "target": "Fray", "type":"E"},
{"source": "Fray", "target": "Mauer", "type":"A"},
{"source": "Fray", "target": "Cynthia", "type":"A"},
{"source": "Fray", "target": "Percy", "type":"A"},
{"source": "Percy", "target": "Cynthia", "type":"A"},
{"source": "Infante", "target": "Duke", "type":"A"},
{"source": "Duke", "target": "Gordon", "type":"A"},
{"source": "Duke", "target": "Sylvester", "type":"A"},
{"source": "Baron", "target": "Duke", "type":"A"},
{"source": "Baron", "target": "Sylvester", "type":"E"},
{"source": "Evette", "target": "Sylvester", "type":"E"},
{"source": "Cynthia", "target": "Sylvester", "type":"E"},
{"source": "Cynthia", "target": "Jamie", "type":"E"},
{"source": "Mauer", "target": "Jessie", "type":"E"},
{"source": "Duke", "target": "Lexy", "type":"A"},
{"source": "Feyton", "target": "Lexy", "type":"A"},
{"source": "Maria", "target": "Feyton", "type":"A"},
{"source": "Baron", "target": "Yvette", "type":"E"},
{"source": "Evette", "target": "Maria", "type":"E"},
{"source": "Cynthia", "target": "Yvette", "type":"E"},
{"source": "Maria", "target": "Jamie", "type":"E"},
{"source": "Maria", "target": "Lesley", "type":"E"},
{"source": "Ashley", "target": "Damo", "type":"A"},
{"source": "Damo", "target": "Lexy", "type":"A"},
{"source": "Maria", "target": "Feyton", "type":"A"},
{"source": "Finkler", "target": "Ashley", "type":"E"},
{"source": "Sylvester", "target": "Maria", "type":"E"},
{"source": "Peter", "target": "Finkler", "type":"E"},
{"source": "Ashley", "target": "Gordon", "type":"E"},
{"source": "Maria", "target": "Imogen", "type":"E"}
//set up the simulation
var simulation = d3.forceSimulation()
//add nodes
var link_force = d3.forceLink(links_data)
.id(function(d) { return; });
var charge_force = d3.forceManyBody()
var center_force = d3.forceCenter(width / 2, height / 2);
//High strength value causes unstable effects
var collide_force = d3.forceCollide(radius)
.force("charge_force", charge_force)
.force("center_force", center_force)
.force("collide", collide_force)
//add tick instructions:
simulation.on("tick", tickActions );
//draw lines for the links
var link = svg.append("g")
.attr("class", "links")
.attr("stroke-width", 2)
.style("stroke", linkColour);
//draw circles for the nodes
var node = svg.append("g")
.attr("class", "nodes")
.attr("r", radius)
.attr("fill", circleColour);
var drag_handler = d3.drag()
.on("start", drag_start)
.on("drag", drag_drag)
.on("end", drag_end);
/** Functions **/
//Function to choose what color circle we have
//Let's return blue for males and red for females
function circleColour(d){
if( =="M"){
return "blue";
} else {
return "pink";
//Function to choose the line colour and thickness
//If the link type is "A" return green
//If the link type is "E" return red
function linkColour(d){
if(d.type == "A"){
return "green";
} else {
return "red";
//drag handler
//d is the node
function drag_start(d) {
if (! simulation.alphaTarget(0.3).restart();
d.fx = d.x;
d.fy = d.y;
function drag_drag(d) {
d.fx = d3.event.x;
d.fy = d3.event.y;
function drag_end(d) {
if (! simulation.alphaTarget(0);
d.fx = null;
d.fy = null;
function tickActions() {
//update circle positions each tick of the simulation
.attr("cx", function(d) { return d.x; })
.attr("cy", function(d) { return d.y; });
//update link positions
.attr("x1", function(d) { return d.source.x; })
.attr("y1", function(d) { return d.source.y; })
.attr("x2", function(d) { return; })
.attr("y2", function(d) { return; });
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